Multi-band power amplifier module

ABSTRACT

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.

This application claims priority from Japanese Patent Application No.2017-192846 filed on Oct. 2, 2017 and Japanese Patent Application No.2017-097149 filed on May 16, 2017. The contents of these applicationsare incorporated herein by reference in its entirety.

The present disclosure relates to a multi-band power amplifier module.Against the backdrop of high-density packaging for mobile communicationterminals such as cellular phones, studies are being made on thereduction in the number of components by sharing various components suchas an antenna switch, an input switch, an output switch, a duplexer, apower amplifier circuit, a low-noise amplifier circuit, and a matchingcircuit.

For example, U.S. Patent Application Publication No. 2016/0119015discloses a power amplifier module having M inputs and N outputs, eachof at least two or more of the M inputs being coupled to a switch thatseparates paths. The power amplifier module includes a plurality offilter circuits and a single power amplifier circuit.

With the recent increase in communication traffic handled by a mobilecommunication terminal, communication technology called carrieraggregation (CA) in which a plurality of frequency ranges (bands) aresimultaneously used is under development. Using CA, a mobilecommunication terminal can increase its communication speed orcommunication quality.

However, U.S. Patent Application Publication No. 2016/0119015 does notdescribe a configuration of the power amplifier module for supportingCA. For example, in a configuration supporting CA, it is conceivablethat an output terminal of a power amplifier circuit is connected to asingle path or connected to two paths. In this case, the matching statebetween an output impedance of the power amplifier circuit and a loadimpedance changes depending on whether the output terminal is connectedto a single path or to two paths. Thus, when the power amplifier moduledescribed in U.S. Patent Application Publication No. 2016/0119015 isapplied to CA, the degree of impedance matching may decrease and theefficiency of amplification of transmission signals using the poweramplifier module may be reduced.

BRIEF SUMMARY

The present disclosure provides a multi-band power amplifier module withimproved efficiency of amplification of transmission signals.

According to some embodiments of the present disclosure, a multi-bandpower amplifier module includes at least one transmission inputterminal, at least one power amplifier circuit that receives a firsttransmission signal and a second transmission signal through the atleast one transmission input terminal, a first filter circuit thatallows the first transmission signal to pass therethrough, a secondfilter circuit that allows the second transmission signal to passtherethrough, at least one transmission output terminal through whichthe first and second transmission signals output from the first andsecond filter circuits are output, a transmission output switch thatoutputs each of the first and second transmission signals output fromthe at least one power amplifier circuit to the first filter circuit orthe second filter circuit, and a first tuning circuit that adjustsimpedance matching between the at least one power amplifier circuit andthe at least one transmission output terminal.

According to other embodiments of the present disclosure, a multi-bandpower amplifier module includes at least one transmission input terminalthat receives a first transmission signal and a second transmissionsignal, at least one power amplifier circuit that receives the firsttransmission signal and the second transmission signal through the atleast one transmission input terminal, a first filter circuit thatallows the first transmission signal to pass therethrough, a secondfilter circuit that allows the second transmission signal to passtherethrough, at least one transmission output terminal through whichthe first and second transmission signals output from the first andsecond filter circuits are output, a transmission input switch thatoutputs each of the first and second transmission signals input throughthe at least one transmission input terminal to one of the at least onepower amplifier circuit, and a first tuning circuit that adjustsimpedance matching between the at least one power amplifier circuit andthe at least one transmission output terminal.

According to embodiments of the present disclosure, it may be possibleto provide a multi-band power amplifier module with improved efficiencyof amplification of transmission signals.

Other features, elements, characteristics and advantages of the presentdisclosure will become more apparent from the following detaileddescription of embodiments of the present disclosure with reference tothe attached drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a block diagram schematically illustrating a circuitconfiguration of a multi-band power amplifier module according to afirst embodiment;

FIG. 2 is a block diagram schematically illustrating a circuitconfiguration of a multi-band power amplifier module according to asecond embodiment;

FIG. 3 is a block diagram schematically illustrating a circuitconfiguration of a multi-band power amplifier module according to athird embodiment;

FIG. 4 is a block diagram illustrating a circuit configuration forimpedance simulation in Example;

FIG. 5 is a block diagram illustrating a circuit configuration forimpedance simulation in Comparative Example;

FIG. 6 is a graph depicting simulation results of band 5; and

FIG. 7 is a graph depicting simulation results of band 12.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described hereinafter withreference to the drawings. In a second embodiment and the subsequentembodiments, the same or similar constituent elements as or to those ina first embodiment are identified with the same or similar numerals asor to those in the first embodiment and are not described in detail, asappropriate. In addition, advantages achieved by the second embodimentand the subsequent embodiments that are similar to those achieved by thefirst embodiment are not described, as appropriate. The drawingsillustrating the embodiments are illustrative and are not to scale, andthe technical scope of the present disclosure should not be construed asbeing limited to these embodiments.

First Embodiment

First, the configuration of a multi-band power amplifier module 100according to a first embodiment of the present disclosure will bedescribed with reference to FIG. 1. FIG. 1 is a block diagramschematically illustrating a circuit configuration of the multi-bandpower amplifier module 100 according to the first embodiment.

The multi-band power amplifier module 100 is a radio-frequency (RF)module included in a mobile communication terminal such as a cellularphone supporting a carrier aggregation (CA) scheme and configured toamplify the power of a transmission signal to a level necessary totransmit the transmission signal to a base station. The transmissionsignal is, for example, a radio frequency (RF) signal modulated inaccordance with a predetermined communication scheme by using a radiofrequency integrated circuit (RFIC) or the like.

The CA scheme is a communication scheme for simultaneously sending andreceiving a plurality of transmission signals and a plurality ofreception signals to and from a base station by using a plurality offrequency ranges (bands). The CA scheme provides improvements incommunication speed or connection stability compared with acommunication scheme for transmission and reception using a single band.The bands used in the multi-band power amplifier module 100 are notlimited specifically and can be selected appropriately from among, forexample, Evolved Universal Terrestrial Radio Access (E-UTRA) band 1(uplink: 1920 MHz-1980 MHz, downlink: 2110 MHz-2170 MHz), . . . , andband 255.

The multi-band power amplifier module 100 may support any of intra-bandcontiguous CA, intra-band non-contiguous CA, and inter-bandnon-contiguous CA. Intra-band contiguous CA uses contiguous componentcarriers (CCs) in the same band as a plurality of transmission signalsto be amplified. Intra-band non-contiguous CA uses non-contiguous CCs inthe same band as a plurality of transmission signals to be amplified.Inter-band non-contiguous CA uses non-contiguous CCs in different bandsas a plurality of transmission signals to be amplified.

The number of CCs to be used is not limited to any value, and themulti-band power amplifier module 100 may support 2UL-CA in which twouplink CCs are used or 3UL-CA in which three uplink CCs are used.Examples of 2UL-CA include a combination of band 2 (uplink: 1850MHz-1910 MHz) and band (uplink: 699 MHz-716 MHz), a combination of band4 (uplink: 1710 MHz-1755 MHz) and band 12, a combination of band 3(uplink: 1710 MHz-1785 MHz) and band 41 (uplink: 2496 MHz-2690 MHz), anda combination of band 8 (uplink: 880 MHz-915 MHz) and band 41. Examplesof 3UL-CA include a combination of band 2, band 12, and band 30, and acombination of band 4, band 12, and band 30.

The multi-band power amplifier module 100 includes a plurality oftransmission input terminals IN1, IN2, . . . , and INh, a transmissioninput switch SW1, a plurality of power amplifier circuits PA1, PA2, . .. , and PAi, a transmission output switch SW2, a first tuning circuitTNG1, a plurality of multiplexers (filter circuits) MPX1, MPX2, . . . ,and MPXj, and a plurality of transmission output terminals ANT1, ANT2, .. . , and ANTj. The multi-band power amplifier module 100 amplifies aplurality of transmission signals TX1, TX2, . . . , and TXj. Themulti-band power amplifier module 100 further includes a configuration(not illustrated) for amplifying received signals and is capable ofamplifying a plurality of received signals RX1, RX2, . . . , and RXk.The multi-band power amplifier module 100 may not be configured toamplify received signals.

The plurality of transmission input terminals IN1, IN2, . . . , and INhare terminals through which the plurality of transmission signals TX1,TX2, . . . , and TXj are input from the outside to the multi-band poweramplifier module 100. For example, the transmission signal TX1 is inputthrough the transmission input terminal IN1, and the transmission signalTX2 is input through the transmission input terminal IN2. In the exampleconfiguration illustrated in FIG. 1, h is an integer greater than orequal to 3, and the multi-band power amplifier module 100 includes htransmission input terminal IN1, IN2, . . . , and INh. In the exampleconfiguration illustrated in FIG. 1, furthermore, j is an integergreater than or equal to 3, and the multi-band power amplifier module100 amplifies and outputs j transmission signals TX1, TX2, . . . , andTXj. It is desirable that the multi-band power amplifier module 100 becapable of amplifying at least two transmission signals and the numberof transmission signals j be greater than or equal to 2. When theplurality of transmission signals TX1, TX2, . . . , and TXj of differentCCs are respectively input through the plurality of transmission inputterminals IN1, IN2, . . . , and INh, the number of transmission inputterminals is equal to the number of transmission signals, that is, h=j.

A plurality of transmission signals may be input through a singletransmission input terminal. For example, the transmission signals TX1and TX2 may be input through the transmission input terminal IN1. In themulti-band power amplifier module 100, therefore, the number oftransmission input terminals may be smaller than the number oftransmission signals, that is, h<j. It is desirable that the multi-bandpower amplifier module 100 include at least one transmission inputterminal, that is, 1≤h≤j.

The transmission input switch SW1 outputs each of the plurality oftransmission signals TX1, TX2, . . . , and TXj, which are input throughthe plurality of transmission input terminals IN1, IN2, . . . , and INh,to one of the plurality of power amplifier circuits PA1, PA2, . . . ,and PAi. The multi-band power amplifier module 100, which includes thetransmission input switch SW1, can selectively input each of theplurality of transmission signals TX1, TX2, . . . , and TXj to asuitable power amplifier circuit. If the CCs of the plurality oftransmission signals TX1, TX2, . . . , and TXj input to the multi-bandpower amplifier module 100 change, the transmission input switch SW1 canswitch paths in accordance with the changes of the CCs. Thus, thereduction in the efficiency of amplification of transmission signals canbe prevented or minimized. The transmission input switch SW1 isoptional. That is, a specific transmission input terminal may be fixedlyconnected to each of a plurality of power amplifier circuits.

The transmission input switch SW1 may output a plurality of transmissionsignals to a single power amplifier circuit or may output a plurality oftransmission signals to different power amplifier circuits. For example,when the respective CCs of the transmission signals TX1 and TX2 areclose to each other or are identical, the transmission input switch SW1outputs the transmission signals TX1 and TX2 to the power amplifiercircuit PA1. When the respective CCs of the transmission signals TX1 andTX2 are far apart from each other, the transmission input switch SW1outputs the transmission signal TX1 to the power amplifier circuit PA1and outputs the transmission signal TX2 to the power amplifier circuitPA2.

The plurality of power amplifier circuits PA1, PA2, . . . , and PAiamplify the power of the plurality of transmission signals TX1, TX2, . .. , and TXj, which are input through the transmission input switch SW1,and output the resulting transmission signals TX1, TX2, . . . , and TXj.In the example illustrated in FIG. 1, i is an integer greater than orequal to 3, and the multi-band power amplifier module 100 includes ipower amplifier circuits PA1, PA2, . . . , and PAi.

The multi-band power amplifier module 100 may include any number ofpower amplifier circuits so long as the plurality of transmissionsignals TX1, TX2, . . . , and TXj can be amplified. For example, whenthe respective CCs of the transmission signals TX1 and TX2 are close toeach other, the power amplifier circuit PA1 may be capable of amplifyingboth the transmission signals TX1 and TX2. Thus, the number i of poweramplifier circuits may be greater than or equal to at least one and lessthan or equal to the number h of transmission input terminals. That is,it is desirable that 1≤i≤h. Accordingly, a reduction in the number i ofpower amplifier circuits results in a reduced size or cost of themulti-band power amplifier module 100.

The transmission output switch SW2 outputs the plurality of transmissionsignals TX1, TX2, . . . , and TXj, which are output from the pluralityof power amplifier circuits PA1, PA2, . . . , and PAi, to the pluralityof multiplexers MPX1, MPX2, . . . , and MPXj, respectively. Themulti-band power amplifier module 100, which includes the transmissionoutput switch SW2, can selectively input each of the plurality oftransmission signals TX1, TX2, . . . , and TXj to a suitablemultiplexer. If the CCs of the plurality of transmission signals TX1,TX2, . . . , and TXj output from the plurality of power amplifiercircuits PA1, PA2, . . . , and PAi change, the transmission outputswitch SW2 can switch paths in accordance with the changes of the CCs.Thus, loss of transmission signals due to the presence of multiplexerscan be reduced.

The transmission output switch SW2 may connect a single power amplifiercircuit to a plurality of multiplexers or may connect each of aplurality of power amplifier circuits to a different multiplexer. Forexample, the power amplifier circuit PA1 amplifies the transmissionsignals TX1 and TX2. In this case, the transmission output switch SW2simultaneously selects a first path for outputting the transmissionsignal TX1 from the power amplifier circuit PA1 to the multiplexer MPX1and a second path for outputting the transmission signal TX2 from thepower amplifier circuit PA1 to the multiplexer MPX2. Alternatively, thepower amplifier circuit PA1 amplifies the transmission signal TX1, andthe power amplifier circuit PA2 amplifies the transmission signal TX2.In this case, the transmission output switch SW2 selects a first pathfor outputting the transmission signal TX1 from the power amplifiercircuit PA1 to the multiplexer MPX1 and a third path for outputting thetransmission signal TX2 from the power amplifier circuit PA2 to themultiplexer MPX2. Thus, the number i of power amplifier circuits may besmaller than the number j of multiplexers. Accordingly, a reduction inthe number i of power amplifier circuits results in a reduced size andcost of the multi-band power amplifier module 100.

The first tuning circuit TNG1 adjusts the impedance matching statebetween the plurality of power amplifier circuits PA1, PA2, . . . , andPAi and the plurality of transmission output terminals ANT1, ANT2, . . ., and ANTj. The first tuning circuit TNG1 is connected between thetransmission output switch SW2 and the plurality of multiplexers MPX1,MPX2, . . . , and MPXj. The first tuning circuit TNG1 includes, forexample, a digitally tunable capacitor (DTC). The multi-band poweramplifier module 100, which includes the first tuning circuit TNG1, canprevent or minimize the reduction in the efficiency of amplification ofa transmission signal caused by a change in matching state between anoutput impedance of a power amplifier circuit and a load impedance. In aconfiguration including the transmission output switch SW2 capable ofselecting a path that connects a power amplifier circuit and amultiplexer, if the matching state between an output impedance of apower amplifier circuit and a load impedance changes depending on thepath selected by the transmission output switch SW2, the first tuningcircuit TNG1 can appropriately adjust impedance matching.

As an example, when the transmission output switch SW2 simultaneouslyselects the first and second paths as paths to be connected to the poweramplifier circuit PA1, the impedance matching state is different fromthat when only the first path is selected as a path to be connected tothe power amplifier circuit PA1. For example, a circuit design is madesuch that the output impedance of the power amplifier circuit PA1 ismatched to the load impedance when only the first path is selected as apath to be connected to the power amplifier circuit PA1. In this case,the first tuning circuit TNG1 adjusts impedance matching in accordancewith a change in impedance matching state, thereby preventing orminimizing the reduction in the efficiency of amplification of thetransmission signal TX1 when the transmission output switch SW2simultaneously selects the first and second paths. Also, for the secondpath, the first tuning circuit TNG1 adjusts impedance matching, therebypreventing or minimizing the reduction in the efficiency ofamplification of the transmission signal TX2.

As another example, the multi-band power amplifier module 100 changesthe output level of the transmission signal TX1, that is, themagnification of the transmission signal TX1 at the power amplifiercircuit PA1, in accordance with the distance between the mobilecommunication terminal and the base station. For example, a circuitdesign is made such that the output impedance of the power amplifiercircuit PA1 is matched to the load impedance when the transmissionsignal TX1 output from the power amplifier circuit PA1 to themultiplexer MPX1 has a specific output level. In this case, the firsttuning circuit TNG1 adjusts the impedance matching state in accordancewith the output level of the transmission signal TX1, thereby preventingor minimizing the reduction in the efficiency of amplification of thetransmission signal TX1.

It is desirable that the first tuning circuit TNG1 be capable ofpreventing or minimizing the reduction in the efficiency ofamplification of at least one transmission signal among at least twotransmission signals to be amplified in the multi-band power amplifiermodule 100. For example, the first tuning circuit TNG1 may be configuredto override preventing or minimizing the reduction in the efficiency ofamplification of the most important transmission signal of at least twotransmission signals while permitting the efficiency of amplification ofthe other transmission signal(s) to remain reduced.

The first tuning circuit TNG1 may be connected between the plurality ofpower amplifier circuits PA1, PA2, . . . , and PAi and the transmissionoutput switch SW2. That is, the first tuning circuit TNG1 may beconnected to the plurality of power amplifier circuits PA1, PA2, . . . ,and PAi, the transmission output switch SW2 may be connected to thefirst tuning circuit TNG1, and the plurality of multiplexers MPX1, MPX2,. . . , and MPXj may be connected to the transmission output switch SW2.This configuration can also adjust the impedance matching state inaccordance with paths of the plurality of transmission signals TX1, TX2,. . . , and TXj that are selected by the transmission output switch SW2.

The plurality of multiplexers MPX1, MPX2, . . . , and MPXj correspond tofilter circuits that allow transmission signals of different CCs to passtherethrough. Each multiplexer may be a duplexer. The multi-band poweramplifier module 100 includes at least two multiplexers to amplify andoutput at least two transmission signals of different CCs. For example,the multiplexer MPX1 allows the transmission signal TX1 to passtherethrough and blocks the transmission signal TX2. The multiplexerMPX2 blocks the transmission signal TX1 and allows the transmissionsignal TX2 to pass therethrough. In the example illustrated in FIG. 1, jis an integer greater than or equal to 3, and the multi-band poweramplifier module 100 includes j multiplexers MPX1, MPX2, . . . , andMPXj.

The plurality of transmission output terminals ANT1, ANT2, . . . , andANTj are coupled to the plurality of multiplexers MPX1, MPX2, . . . ,and MPXj, respectively, and output the plurality of transmission signalsTX1, TX2, . . . , and TXj, respectively. The plurality of transmissionoutput terminals ANT1, ANT2, . . . , and ANTj are connected to externalantennas. For example, the transmission output terminal ANT1 outputs thetransmission signal TX1 output from the multiplexer MPX1, and thetransmission output terminal ANT2 outputs the transmission signal TX2output from the multiplexer MPX2. The plurality of transmission outputterminals ANT1, ANT2, . . . , and ANTj are capable of inputting theplurality of received signals RX1, RX2, . . . , and RXk to the pluralityof multiplexers MPX1, MPX2, . . . , and MPXj.

Other embodiments will be described hereinafter. In the followingembodiments, features common to the first embodiment and the followingembodiments are not described but only differences are described.Elements assigned numerals similar to those of the first embodiment haveconfigurations and functions similar to those of the elements in thefirst embodiment and are not described in detail. Similar operationaladvantages achieved by similar elements are not described.

Second Embodiment

Next, the configuration of a multi-band power amplifier module 200according to a second embodiment of the present disclosure will bedescribed with reference to FIG. 2. FIG. 2 is a block diagramschematically illustrating a circuit configuration of the multi-bandpower amplifier module 200 according to the second embodiment.

The multi-band power amplifier module 200 includes the plurality oftransmission input terminals IN1, IN2, . . . , and INh, the transmissioninput switch SW1, the plurality of power amplifier circuits PA1, PA2, .. . , and PAi, the transmission output switch SW2, the first tuningcircuit TNG1, the plurality of multiplexers MPX1, MPX2, . . . , andMPXj, and a plurality of transmission output terminals ANT1, . . . , andANTp.

The multi-band power amplifier module 200 further includes an antennaswitch SW3. The antenna switch SW3 switches paths between the pluralityof multiplexers MPX1, MPX2, . . . , and MPXj and the plurality oftransmission output terminals ANT1, . . . , and ANTp. In the exampleconfiguration illustrated in FIG. 2, p is an integer greater than orequal to 2, and the multi-band power amplifier module 200 includes ptransmission output terminals ANT1, . . . , and ANTp. It is desirablethat the multi-band power amplifier module 200 include at least onetransmission output terminal, that is, 1≤p≤j.

As an example, the frequencies of the CCs of the transmission signal TX1output from the multiplexer MPX1 and the transmission signal TX2 outputfrom the multiplexer MPX2 are close to each other. In this case, theantenna switch SW3 can output the transmission signals TX1 and TX2 tothe transmission output terminal ANT1 and can emit the transmissionsignals TX1 and TX2 from the same external antenna. Accordingly, thenumber p of transmission output terminals can be reduced.

Third Embodiment

Next, the configuration of a multi-band power amplifier module 300according to a third embodiment of the present disclosure will bedescribed with reference to FIG. 3. FIG. 3 is a block diagramschematically illustrating a circuit configuration of the multi-bandpower amplifier module 300 according to the third embodiment.

The multi-band power amplifier module 300 includes the plurality oftransmission input terminals IN1, IN2, . . . , and INh, the transmissioninput switch SW1, the plurality of power amplifier circuits PA1, PA2, .. . , and PAi, the transmission output switch SW2, the first tuningcircuit TNG1, the plurality of multiplexers MPX1, MPX2, . . . , andMPXj, the antenna switch SW3, and the plurality of transmission outputterminals ANT1, . . . , and ANTp.

The multi-band power amplifier module 300 further includes a receptioninput switch SW4, a second tuning circuit TNG2, a plurality of low-noiseamplifier circuits LNA1, LNA2, . . . , and LNAm, and a plurality ofreception output terminals OUT1, OUT2, . . . , and OUTn.

The reception input switch SW4 outputs each of the plurality of receivedsignals RX1, RX2, . . . , and RXk, which are input through the pluralityof transmission output terminals ANT1, . . . , and ANTp via theplurality of multiplexers MPX1, MPX2, . . . , and MPXj, to one of theplurality of low-noise amplifier circuits LNA1, LNA2, . . . , and LNAm.The multi-band power amplifier module 300, which includes the receptioninput switch SW4, can selectively input each of the plurality ofreceived signals RX1, RX2, . . . , and RXk to a suitable low-noiseamplifier circuit. If the CCs of the plurality of received signals RX1,RX2, . . . , and RXk input to the multi-band power amplifier module 300change, the reception input switch SW4 can switch paths in accordancewith the changes of the CCs. Thus, the reduction in the efficiency ofamplification of received signals can be prevented or minimized. Thereception input switch SW4 is optional. That is, a specific multiplexermay be fixedly connected to each of a plurality of low-noise amplifiercircuits.

The reception input switch SW4 may input two or more received signals toa single low-noise amplifier circuit or may input two or more receivedsignals to different low-noise amplifier circuits. For example, when thefrequencies of the respective CCs of the received signals RX1 and RX2are close to each other or the bands of the respective CCs of thereceived signals RX1 and RX2 are identical, the reception input switchSW4 outputs the received signals RX1 and RX2 to the low-noise amplifiercircuit LNA1. When the respective CCs of the received signals RX1 andRX2 are far apart from each other, the reception input switch SW4outputs the received signal RX1 to the low-noise amplifier circuit LNA1and outputs the received signal RX2 to the low-noise amplifier circuitLNA2.

The second tuning circuit TNG2 adjusts the impedance matching statebetween the plurality of multiplexers MPX1, MPX2, . . . , and MPXj andthe plurality of low-noise amplifier circuits LNA1, LNA2, . . . , andLNAm. The second tuning circuit TNG2 is connected between the receptioninput switch SW4 and the plurality of low-noise amplifier circuits LNA1,LNA2, . . . , and LNAm. The multi-band power amplifier module 300, whichincludes the second tuning circuit TNG2, can prevent or minimize thereduction in the efficiency of amplification of a received signal causedby a change in matching state between an output impedance of a low-noiseamplifier circuit and a load impedance. For example, in a configurationincluding the reception input switch SW4 capable of selecting a paththat connects a multiplexer and a low-noise amplifier circuit, ifimpedance matching between a multiplexer and a low-noise amplifiercircuit is changed in accordance with a path selected by the receptioninput switch SW4, the second tuning circuit TNG2 can appropriatelyadjust impedance matching.

As an example, when the reception input switch SW4 simultaneouslyconnects the multiplexers MPX1 and MPX2 to the low-noise amplifiercircuit LNA1, the impedance matching state is different from that whenonly the multiplexer MPX1 is connected to the low-noise amplifiercircuit LNA1. A circuit design is made such that the output impedance ofthe low-noise amplifier circuit LNA1 is matched to the load impedancewhen only the multiplexer MPX1 is connected to the low-noise amplifiercircuit LNA1. In this case, the second tuning circuit TNG2 adjustsimpedance matching in accordance with a change in impedance matchingstate, thereby preventing or minimizing the reduction in the efficiencyof amplification of the received signal RX1 when both the multiplexersMPX1 and MPX2 are connected to the low-noise amplifier circuit LNA1.

The second tuning circuit TNG2 may be connected between the plurality ofmultiplexers MPX1, MPX2, . . . , and MPXj and the reception input switchSW4. That is, the second tuning circuit TNG2 may be connected to theplurality of multiplexers MPX1, MPX2, . . . , and MPXj, the receptioninput switch SW4 may be connected to the second tuning circuit TNG2, andthe plurality of low-noise amplifier circuits LNA1, LNA2, . . . , andLNAm may be connected to the reception input switch SW4. Thisconfiguration can also adjust the impedance matching state in accordancewith paths of the plurality of received signals RX1, RX2, . . . , andRXk that are selected by the reception input switch SW4.

The plurality of low-noise amplifier circuits LNA1, LNA2, . . . , andLNAm amplify and output the plurality of received signals RX1, RX2, . .. , and RXk, respectively. In the example illustrated in FIG. 3, m is aninteger greater than or equal to 3, and the multi-band power amplifiermodule 300 includes m low-noise amplifier circuits LNA1, LNA2, . . . ,and LNAm. In the example configuration illustrated in FIG. 3, the numberm of low-noise amplifier circuits is an integer greater than or equal to3, which is equal to the number of received signals k, that is, m=k. Itis desirable that the multi-band power amplifier module 300 include atleast one low-noise amplifier circuit, and a plurality of receivedsignals may be amplified by using a single low-noise amplifier circuit.Thus, it is desirable that 1≤m≤k.

The plurality of reception output terminals OUT1, OUT2, . . . , and OUTnare terminals through which the plurality of received signals RX1, RX2,. . . , and RXk amplified by the plurality of low-noise amplifiercircuits LNA1, LNA2, . . . , and LNAm are respectively output. Theplurality of reception output terminals OUT1, OUT2, . . . , and OUTn areconnected to the plurality of low-noise amplifier circuits LNA1, LNA2, .. . , and LNAm. In the example configuration illustrated in FIG. 3, thenumber n of reception output terminals is greater than or equal to 3,which is equal to the number m of low-noise amplifier circuits. That is,n=m. It is desirable that the multi-band power amplifier module 300include at least one reception output terminal, that is, 1≤n≤k.

Simulation Evaluation

Next, simulation evaluation for the advantages achieved by themulti-band power amplifier modules 100, 200, and 300 according to therespective embodiments will be described with reference to FIGS. 4 to 7.FIG. 4 is a block diagram illustrating a circuit configuration inExample. FIG. 5 is a block diagram illustrating a circuit configurationin Comparative Example. FIG. 6 is a graph depicting simulation resultsof band 5. FIG. 7 is a graph depicting simulation results of band 12.

As illustrated in FIG. 4, a circuit according to Example includes atransmission input terminal IN, a power amplifier circuit PA, atransmission output switch SW, a tuning circuit TNG, two multiplexersMPX-B5 and MPX-B12, and two transmission output terminals ANT-B5 andANT-B12. The transmission output switch SW connects the power amplifiercircuit PA to the multiplexer MPX-B5 and also connects the poweramplifier circuit PA to the multiplexer MPX-B12. In this circuit, atransmission signal TX-B5 of band 5 (uplink: 824 MHz-849 MHz) and atransmission signal TX-B12 of band 12 (uplink: 699 MHz-716 MHz) aresimultaneously input through the transmission input terminal IN. Thetransmission signal TX-B5 passes through the multiplexer MPX-B5 and isoutput through the transmission output terminal ANT-B5. The transmissionsignal TX-B12 passes through the multiplexer MPX-B12 and is outputthrough the transmission output terminal ANT-B12.

As illustrated in FIG. 5, Comparative Example provides a configurationobtained by removing the tuning circuit TNG from the circuit accordingto Example. Also, in Comparative Example, the transmission signal TX-B5of band 5 and the transmission signal TX-B12 of band 12 aresimultaneously input through the transmission input terminal IN. For thepath between the power amplifier circuit PA and the multiplexer MPX-B5,the output impedance of the power amplifier circuit PA is set to bematched to the load impedance when the multiplexer MPX-B5 is connectedalone to the power amplifier circuit PA without necessarily theintervention of a tuning circuit. For the path between the poweramplifier circuit PA and the multiplexer MPX-B12, the output impedanceof the power amplifier circuit PA is set to be matched to the loadimpedance when the multiplexer MPX-B12 is connected alone to the poweramplifier circuit PA without necessarily the intervention of a tuningcircuit.

The scattering parameters (S-parameters) on the transmission outputterminal ANT-B5 side in Example and Comparative Example were simulatedby using as a reference the S-parameter obtained when the multiplexerMPX-B5 is connected alone to the power amplifier circuit PA withoutnecessarily the intervention of a tuning circuit. Also, the S-parameterson the transmission output terminal ANT-B12 side in Example andComparative Example were simulated by using as a reference theS-parameter obtained when the multiplexer MPX-B12 is connected alone tothe power amplifier circuit PA without necessarily the intervention of atuning circuit.

As illustrated in FIG. 6, the S-parameter on the transmission outputterminal ANT-B5 side in Example is enhanced compared with theS-parameter on the transmission output terminal ANT-B5 side inComparative Example. As illustrated in FIG. 7, the S-parameter on thetransmission output terminal ANT-B12 side in Example is enhancedcompared with the S-parameter on the transmission output terminalANT-B12 side in Comparative Example.

As described above, an aspect of the present disclosure provides amulti-band power amplifier module including at least one transmissioninput terminal, at least one power amplifier circuit that receives afirst transmission signal and a second transmission signal through theat least one transmission input terminal, a first filter circuit thatallows the first transmission signal to pass therethrough, a secondfilter circuit that allows the second transmission signal to passtherethrough, at least one transmission output terminal through whichthe first and second transmission signals output from the first andsecond filter circuits are output, a transmission output switch thatoutputs each of the first and second transmission signals output fromthe at least one power amplifier circuit to the first filter circuit orthe second filter circuit, and a first tuning circuit that adjustsimpedance matching between the at least one power amplifier circuit andthe at least one transmission output terminal.

According to the aspect described above, a tuning circuit can prevent orminimize the reduction in the efficiency of amplification of atransmission signal caused by a change in matching state between anoutput impedance of a power amplifier circuit and a load impedance. Inaddition, a transmission output switch enables each of a plurality oftransmission signals to be selectively input to a suitable filtercircuit. If the CCs of a plurality of transmission signals respectivelyoutput from a plurality of power amplifier circuits change, thetransmission output switch can switch paths in accordance with thechanges of the CCs. Thus, each transmission signal can be output to anoptimum filter circuit, and loss of transmission signals can be reduced.Furthermore, if the matching state between an output impedance of apower amplifier circuit and a load impedance changes depending on thepath selected by the transmission output switch, the tuning circuit canappropriately adjust impedance matching. Since the transmission outputswitch is capable of separating transmission signals, the number ofpower amplifier circuits can be smaller than the number of filtercircuits. This configuration can reduce the size and cost of themulti-band power amplifier module.

The multi-band power amplifier module may further include a transmissioninput switch that outputs each of the first and second transmissionsignals input through the at least one transmission input terminal toone of the at least one power amplifier circuit. This configurationenables each of a plurality of transmission signals to be selectivelyinput to a suitable power amplifier circuit. If the CCs of a pluralityof transmission signals input to the multi-band power amplifier modulechange, the transmission input switch can switch paths in accordancewith the changes of the CCs. Thus, the reduction in the efficiency ofamplification of transmission signals can be prevented or minimized. Inaddition, since the transmission input switch is capable of separatingtransmission signals, the number of power amplifier circuits can besmaller than the number of transmission input terminals. Thisconfiguration can reduce the size and cost of the multi-band poweramplifier module.

The at least one power amplifier circuit may include a first poweramplifier circuit configured to amplify both the first transmissionsignal and the second transmission signal, and the transmission outputswitch may simultaneously select a first path for outputting the firsttransmission signal from the first power amplifier circuit to the firstfilter circuit and a second path for outputting the second transmissionsignal from the first power amplifier circuit to the second filtercircuit. With this configuration, the number of power amplifier circuitscan be smaller than the number of filter circuits. In addition, the sizeand cost of the multi-band power amplifier module can be reduced.

The first tuning circuit may adjust impedances in accordance with achange in impedance matching state between when the transmission outputswitch selects the first path and when the transmission output switchselects both the first path and the second path. With thisconfiguration, if a plurality of filter circuits is coupled to a singlepower amplifier circuit through the transmission output switch, thereduction in the efficiency of amplification of transmission signals inthe power amplifier circuit can be prevented or minimized.

The first tuning circuit may be connected between the transmissionoutput switch and the first and second filter circuits.

Another aspect of the present disclosure provides a multi-band poweramplifier module including at least one transmission input terminal thatreceives a first transmission signal and a second transmission signal,at least one power amplifier circuit that receives the firsttransmission signal and the second transmission signal through the atleast one transmission input terminal, a first filter circuit thatallows the first transmission signal to pass therethrough, a secondfilter circuit that allows the second transmission signal to passtherethrough, at least one transmission output terminal through whichthe first and second transmission signals output from the first andsecond filter circuits are output, a transmission input switch thatoutputs each of the first and second transmission signals input throughthe at least one transmission input terminal to one of the at least onepower amplifier circuit, and a first tuning circuit that adjustsimpedance matching between the at least one power amplifier circuit andthe at least one transmission output terminal.

According to the aspect described above, a tuning circuit can prevent orminimize the reduction in the efficiency of amplification of atransmission signal caused by a change in matching state between anoutput impedance of a power amplifier circuit and a load impedance. Atransmission input switch is capable of selectively inputting each of aplurality of transmission signals to a suitable power amplifier circuit.If the CCs of a plurality of transmission signals input to themulti-band power amplifier module change, the transmission input switchcan switch paths in accordance with the changes of the CCs. Thus, thereduction in the efficiency of amplification of transmission signals canbe prevented or minimized. In addition, since the transmission inputswitch is capable of separating transmission signals, the number ofpower amplifier circuits can be smaller than the number of transmissioninput terminals. This configuration can reduce the size and cost of themulti-band power amplifier module.

The first tuning circuit may adjust the impedance matching state inaccordance with an output level of at least one of the first and secondtransmission signals in the at least one power amplifier circuit. If thematching state between an output impedance of a power amplifier circuitand a load impedance changes in accordance with a change in outputlevel, a tuning circuit can correct the impedance matching state. Thatis, the reduction in the efficiency of amplification of transmissionsignals in the multi-band power amplifier module, which is caused by theoutput level, can be prevented or minimized. For example, if the outputlevels of the first and second transmission signals are to be adjusted,such as when the distances between a device including the multi-bandpower amplifier module and a plurality of base stations that communicatewith the device are different, the reduction in the efficiency ofamplification of at least one of the first and second transmissionsignals can be prevented or minimized.

The first transmission signal and the second transmission signal may beincluded in an identical frequency range. That is, the multi-band poweramplifier module may be configured to amplify a plurality oftransmission signals in accordance with the intra-band contiguous CAscheme or the intra-band non-contiguous CA scheme.

The first transmission signal and the second transmission signal may beincluded in different frequency ranges. That is, the multi-band poweramplifier module may be configured to amplify a plurality oftransmission signals in accordance with the inter-band non-contiguous CAscheme.

The multi-band power amplifier module may further include an antennaswitch that switches paths between the first and second filter circuitsand the at least one transmission output terminal. With thisconfiguration, the first and second transmission signals can be outputto a single transmission output terminal and can be emitted from thesame external antenna. That is, the number of transmission outputterminals can be reduced.

The multi-band power amplifier module may further include at least onelow-noise amplifier circuit, a reception input switch that outputs eachof a first received signal output from the first filter circuit and asecond received signal output from the second filter circuit to one ofthe at least one low-noise amplifier circuit, and a second tuningcircuit that adjusts impedance matching between the first and secondfilter circuits and the at least one low-noise amplifier circuit.

With this configuration, the reception input switch enables each of aplurality of received signals to be selectively input to a suitablelow-noise amplifier circuit. If the CCs of a plurality of receivedsignals input to the multi-band power amplifier module change, thereception input switch can switch low-noise amplifier circuits to whichthe received signals are input in accordance with the changes of theCCs. Thus, the reduction in the efficiency of amplification of receivedsignals can be prevented or minimized. In addition, a tuning circuit canprevent or minimize the reduction in the efficiency of amplification ofa received signal caused by a change in matching state between an outputimpedance of a low-noise amplifier circuit and a load impedance. In aconfiguration including a reception input switch capable of selecting apath that connects a filter circuit and a low-noise amplifier circuit,the second tuning circuit adjusts impedance matching in accordance witha change in impedance matching state, thereby preventing or minimizingthe reduction in the efficiency of amplification of the first receivedsignal when both the first multiplexer and the second multiplexer areconnected to the first low-noise amplifier circuit.

The second tuning circuit may be connected between the reception inputswitch and the at least one low-noise amplifier circuit.

As described above, according to an aspect of the present disclosure, itmay be possible to provide a multi-band power amplifier module withimproved efficiency of amplification of transmission signals.

The embodiments described above are intended to help easily understandthe present disclosure and are not to be used to construe the presentdisclosure in a limiting fashion. Modifications or improvements may bemade to the present disclosure without necessarily departing from thegist of the present disclosure, and their equivalents are also includedin the present disclosure. That is, the embodiments may be appropriatelymodified in design by those skilled in the art, and such a modificationalso falls within the scope of the present disclosure so long as themodification includes the features of the present disclosure. Forexample, the elements included in the embodiments and the arrangement,materials, conditions, shapes, sizes, and so on thereof are not limitedto those illustrated exemplarily but can be modified as appropriate. Inaddition, it is to be understood that the embodiments are illustrative,and configurations given in different embodiments may be partiallyreplaced or combined. Such a replacement or combination also fallswithin the scope of the present disclosure so long as the replacement orcombination includes the features of the present disclosure.

While embodiments of the disclosure have been described above, it is tobe understood that variations and modifications will be apparent tothose skilled in the art without necessarily departing from the scopeand spirit of the disclosure. The scope of the disclosure, therefore, isto be determined solely by the following claims.

What is claimed is:
 1. A multi-band power amplifier module comprising:at least one transmission input terminal; at least one power amplifiercircuit that receives a first transmission signal and a secondtransmission signal through the at least one transmission inputterminal; a first filter circuit that passes the first transmissionsignal; a second filter circuit that passes the second transmissionsignal; at least one transmission output terminal through which thefirst transmission signal and the second transmission signal from thefirst and second filter circuits are output; a transmission outputswitch that selectively transmits each of the first transmission signaland the second transmission signal output from the at least one poweramplifier circuit to the respective first and second filter circuits;and a first tuning circuit that adjusts impedance matching between theat least one power amplifier circuit and the at least one transmissionoutput terminal.
 2. The multi-band power amplifier module according toclaim 1, further comprising: a transmission input switch that transmitseach of the first transmission signal and the second transmission signalinput through the at least one transmission input terminal to one of theat least one power amplifier circuit.
 3. The multi-band power amplifiermodule according to claim 1, wherein: the at least one power amplifiercircuit comprises a first power amplifier circuit configured to amplifyboth the first transmission signal and the second transmission signal,and the transmission output switch simultaneously selects a first pathconfigured to transmit the first transmission signal from the firstpower amplifier circuit to the first filter circuit and a second pathconfigured to transmit the second transmission signal from the firstpower amplifier circuit to the second filter circuit.
 4. The multi-bandpower amplifier module according to claim 3, wherein the first tuningcircuit adjusts impedances in accordance with a change in impedancematching state associated with the transmission output switch selectingbetween the first path and both the first path and the second path. 5.The multi-band power amplifier module according to claim 1, wherein thefirst tuning circuit is connected between the transmission output switchand the first and second filter circuits.
 6. The multi-band poweramplifier module according to claim 2, wherein the first tuning circuitis connected between the transmission output switch and the first andsecond filter circuits.
 7. The multi-band power amplifier moduleaccording to claim 3, wherein the first tuning circuit is connectedbetween the transmission output switch and the first and second filtercircuits.
 8. A multi-band power amplifier module comprising: at leastone transmission input terminal that receives a first transmissionsignal and a second transmission signal; at least one power amplifiercircuit that receives the first transmission signal and the secondtransmission signal through the at least one transmission inputterminal; a first filter circuit that passes the first transmissionsignal; a second filter circuit that passes the second transmissionsignal; at least one transmission output terminal through which thefirst transmission signal and the second transmission signal from thefirst and second filter circuits are output; a transmission input switchthat selectively transmits each of the first transmission signal and thesecond transmission signal input through the at least one transmissioninput terminal to one of the at least one power amplifier circuit; and afirst tuning circuit that adjusts impedance matching between the atleast one power amplifier circuit and the at least one transmissionoutput terminal.
 9. The multi-band power amplifier module according toclaim 1, wherein the first tuning circuit adjusts an impedance matchingstate in accordance with an output level of at least one of the firsttransmission signal and the second transmission signal in the at leastone power amplifier circuit.
 10. The multi-band power amplifier moduleaccording to claim 1, wherein the first transmission signal and thesecond transmission signal are in an identical frequency range.
 11. Themulti-band power amplifier module according to claim 1, wherein thefirst transmission signal and the second transmission signal are indifferent frequency ranges.
 12. The multi-band power amplifier moduleaccording to claim 1, further comprising an antenna switch thatselectively connects the first filter circuit and the second filtercircuit to the at least one transmission output terminal.
 13. Themulti-band power amplifier module according to claim 1, furthercomprising: at least one low-noise amplifier circuit; a reception inputswitch that selectively transmits each of a first received signal outputfrom the first filter circuit and a second received signal output fromthe second filter circuit to one of the at least one low-noise amplifiercircuit; and a second tuning circuit that adjusts impedance matchingbetween the first and second filter circuits and the at least onelow-noise amplifier circuit.
 14. The multi-band power amplifier moduleaccording to claim 13, wherein the second tuning circuit is connectedbetween the reception input switch and the at least one low-noiseamplifier circuit.
 15. The multi-band power amplifier module accordingto claim 8, wherein the first tuning circuit adjusts an impedancematching state in accordance with an output level of at least one of thefirst transmission signal and the second transmission signal in the atleast one power amplifier circuit.
 16. The multi-band power amplifiermodule according to claim 8, wherein the first transmission signal andthe second transmission signal are in an identical frequency range. 17.The multi-band power amplifier module according to claim 8, wherein thefirst transmission signal and the second transmission signal are indifferent frequency ranges.
 18. The multi-band power amplifier moduleaccording to claim 8, further comprising an antenna switch thatselectively connects the first filter circuit and the second filtercircuit to the at least one transmission output terminal.
 19. Themulti-band power amplifier module according to claim 8, furthercomprising: at least one low-noise amplifier circuit; a reception inputswitch that selectively transmits each of a first received signal outputfrom the first filter circuit and a second received signal output fromthe second filter circuit to one of the at least one low-noise amplifiercircuit; and a second tuning circuit that adjusts impedance matchingbetween the first and second filter circuits and the at least onelow-noise amplifier circuit.
 20. The multi-band power amplifier moduleaccording to claim 19, wherein the second tuning circuit is connectedbetween the reception input switch and the at least one low-noiseamplifier circuit.